Moisture; Dry Shrinkage; Wet Expansion - Viega Climate Trak Installation Manual

Finish Flooring

7.1.2 Moisture

7.1.2.1 Dry Shrinkage

7.1.2.2 Wet Expansion

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Allow the radiant system to run for at least a week before installing the
hardwood. This will ensure that the subfloor is dry. Wood flooring should
be acclimated to the job site before installation. When checking the
moisture content of the subfloor and wood flooring with a moisture meter,
aim for a reading of 6% to 8%. Moisture will affect the hardwood floor
with or without a radiant system.
■ Moisture absorption causes wood to swell.
■ Moisture loss causes wood to shrink.
If the moisture content of the wood is relatively high near the bottom of
the plank, cupping upward will occur exaggerating cracks.
If the moisture content is relatively high near the top surface of the plank,
it will crown downward on the edges.
Sources from below:
■ Inadequate moisture barrier
■ Ground water wicking through the slab
■ Unsealed subfloor
Sources from above:
■ High relative humidity
Both solid plank flooring and engineered wood floors are acceptable
choices over radiant heating.
Choosing narrower planks and harder woods minimizes dimensional
change in the wood. Engineered wood flooring usually has less expansion
and contraction and can be a good choice to minimize gaps between
planks.
Note: Follow the flooring manufacturer's installation manual or NOFMA's
(National Oak Flooring Manufacturers Association) manual.
IM-HC 530590 0621 Climate Trak (EN)